Physiography of Karnataka

Karnataka is situated on the western edge of the Deccan Peninsular region of India. It is located approximately between 11.5° North and 18.5° North latitudes and 74° East and 78.5° East longitudes. Karnataka comprises the Deccan Plateau, the Western Ghats Mountain Range and the Coastal Plains.

Physiograpically, Karnataka is part of two well-defined regions of India: the Deccan Plateau and the Coastal plains and Islands.

Physiographic landforms of Karnataka

The state can be divided into four physiographic landforms – the Northern Karnataka Plateau, the Central Karnataka Plateau, the Southern Karnataka Plateau and the Coastal Karnataka Region.

Northern Karnataka Plateau

The Northern Karnataka Plateau covers the districts of Belgaum, Bidar, Bijapur and Gulbarga. The area is mainly composed of the Deccan Trap. It represents an extensive deforested plateau landscape. The Northern Karnataka Plateau has an elevation of 300 metres to 600 metres from the sea level. The plateau slopes towards the east. The landscape is mainly covered with rich black cotton soils.

The vast expanse of treeless plateau is interspersed with river plains, watersheds, residual hills and ridges. The river plains are represented by those of River Bhima, River Ghataprabha, River Krishna and River Malaprabha.

Central Karnataka Plateau

The Central Karnataka Plateau is located between the Northern Karnataka Plateau and the Southern Karnataka Plateau. It consists of districts like Bellary, Chikmagalur, Chitradurga, Dharwad, Raichur and Shimoga. The elevation of the Central Karnataka Plateau varies between 450 metres and 700 metres. The general slope of this plateau is towards the east.

This region is the location of the Tungabhadra River basin.

Southern Karnataka Plateau

The Southern Karnataka Plateau includes the districts of Bangalore Urban, Bangalore Rural, Hassan, Kodagu, Kolar, Mandya, Mysore and Tumkur. This plateau region is covered by a high degree of slope. It is encircled by the Western Ghats on the west and the south. The Southern Karnataka Plateau has a general elevation of 600 metres to 900 metres. But the Biligirirangan hills of Mysore district and the Brahmagiri range of Kodagu district have residual heights ranging between 1,500 metres to 1,750 metres.

The Cauvery River basin forms a significant part of this plateau.

Karnataka Coastal Region

The Karnataka coastal belt starts from the Western Ghats in the west and extends till the edge of the Karnataka Plateau in the east. The Karnataka Coastal Region includes the districts of Uttara Kannada and Dakshina Kannada.

The terrain of this region consists of rivers, creeks, waterfalls, ranges of hills and peaks. The Karnataka Coastal Region can be divided into two main geographical divisions, known as the Western Ghats and the plains. The coastal belt has an average width of 50 km to 80 km. It covers a distance of around 267 km from north to south.

River Systems of Karnataka

Karnataka has seven river systems and their tributaries flowing through the state. The river systems of Karnataka are:

Cauvery

Godavari

Krishna

North Pennar

South Pennar

Palar

The West Flowing Rivers

Karnataka has 26 east flowing rivers and 10 west flowing rivers. The west flowing rivers of Karnataka flow to the Arabian Sea. These west-flowing rivers are responsible for providing 60% of the state’s inland water resources.

Types of soil in Karnataka

There are eleven different varieties of soil orders found in Karnataka. They are:

Alfisols

Andisols

Aridisols

Entisols

Histosols

Inceptisols

Mollisols

Oxisols

Spodosols

Ultisols

Vertisols

According to soil survey data, the soils of Karnataka can be divided under nine groups. These groups are:

Red Sandy Soils

Red Loamy Soils

Shallow Black Soils

Medium Black Soils

Deep Black Soils

Mixed Red and Black Soils

Laterite Soils

Laterite Gravelly Soils

Coastal Alluvium

Climate of Karnataka

Karnataka has a dynamic weather due to the land’s altitude, topography and the distance from the sea. The climate of Karnataka ranges from arid to semi-arid to humid tropical. Two annual monsoons bring rainfall to Karnataka: the North-East monsoon and the South-West monsoon. The mean annual rainfall in Karnataka is around 1355 millimetres. The coastal region of Karnataka receives the maximum rainfall while parts of North Interior Karnataka is among the major rainfall deficit areas of the state.

Karnataka experiences four seasons in a year. They are:

Summer: Summer starts from March and extends till May. This season is hot, dry and humid.

Monsoon: Monsoon begins in June and lasts until September. During this season the state receives rainfall due to the southwest monsoon winds.

Post-monsoon: Post-monsoon season extends from October to December. This season is quiet pleasant as humidity reduces significantly.

Winter: Winter stays in Karnataka during the months of January and February. The state experiences low temperature and reduced humidity.